Chapter 10 exercises: Operations, GroupBy and Exploratory Analysis
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Attempt these tasks before opening the worked answers. Use the chapter experiment notebook, or import NumPy as np and Pandas as pd in your own notebook. Retain your first attempt and explain each correction.
B2-10-E01 · Count support correctly
Report row count and observed-value count for each group.
df=pd.DataFrame({"group":["A","A","B"],"value":[2,None,5]})One hint after an attempt
Compare size and count on the same group.
B2-10-E02 · Compare weights
Calculate the mean subgroup proportion and pooled proportion; explain their different weighting.
success=np.array([9,30])
total=np.array([10,60])One hint after an attempt
Write both denominators in words.
B2-10-E03 · Check a subgroup reversal
Verify that A has the higher rate in both tasks while B has the higher pooled rate.
a_success=np.array([9,20]);a_total=np.array([10,100])
b_success=np.array([80,1]);b_total=np.array([100,10])One hint after an attempt
Compare each task before summing.
Reflect and get feedback
Explain one result without looking at the code. Identify one boundary case that would change your method. An optional tutor prompt is: “Here is my attempt at B2-10-E03. Give one hint about the violated assumption; do not give the solution yet.” Then use the worked answers.